Wireless terminals may operate in multiple frequency bands (i.e., “multi-band”) to provide operations in multiple communications systems. For example, many cellular radiotelephones are designed for operation in Global System for Mobile Communications (GSM), Wideband Code Division Multiple Access (WCDMA), and Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) modes at nominal frequencies such as 850 Megahertz (MHz), 900 MHz, 1800 MHz, 1900 MHz, and/or 2100 MHz.
Achieving effective performance in multiple frequency bands may be difficult. For example, contemporary wireless terminals are increasingly including more circuitry and larger displays and keypads/keyboards within small housings. Constraints on the available space and locations for antennas in wireless terminals can negatively affect antenna performance.
For example, although wireless terminals may include multiple antennas, mutual coupling between different antennas may degrade performance. Moreover, if a wireless terminal uses its chassis as a shared radiator for multiple antennas operating in low frequency bands (e.g., below about one (1.0) Gigahertz (GHz)), then mutual coupling may particularly degrade performance in the low frequency bands.